jerryc41 wrote:
32GB is a good size, but I would have several - like four. Is the external drive your only storage option? If that fails, you'll have no pictures at all. If you bring a small computer, you can back up to that, as well. Acer has small, inexpensive units. If you fill each card to about 75%, you may be able to leave the images on the cards till you get home. That will give you three copies of your images.
I have a tiny Acer netbook with a 250Gb HDD and a external HDD - Just for the triple back up as you state! The 10inch screen is fine for casually looking at the images. - I also take several 16Gb cards along and never delete any thing until the files are at home and backed up again. Storage is cheap today! P.S. Speed matters if the OP is at all interested in video.